The effect of etching on bacterial microleakage of an adhesive composite restoration.

OBJECTIVES: The incidence of bacterial microleakage, pulp inflammation and necrosis associated with dentine etching treatments prior to restoration are not known. Consequently, to resolve some of the controversy surrounding the effects and importance of vital dentine etching, the authors investigated these factors. METHODS: 110 standardised class V cavities were cut into buccal dentine, without exposing the pulp of teeth scheduled for extraction for orthodontic reasons. Cavities were either left unetched, or etched with the non-equivalent treatments of phosphoric acid gel for 60s or Ethylenediaminetetraacetic acid (EDTA) for 30s, prior to placement of composite resin. Teeth were collected and pulp responses were evaluated according to ISO guidelines, using pathohistomorphometric analysis and ANOVA statistics. RESULTS: Etching was found to be correlated to bacterial microleakage (p=0.0001) and tertiary dentine formation (p=0.0023). Bacterial microleakage was correlated to inflammatory activity (p=0.0001). The frequency of bacterial microleakage was: no etching (65%), EDTA (51%) and phosphoric acid (PA) (20%). SIGNIFICANCE: Vital dentine etching treatment is of extreme importance for the placement of RC to minimise bacterial microleakage. PA etching proved to be more effective at preventing bacterial microleakage than non-etching, and etching with EDTA.     

Intimal hyperplasia and coronary flow reserve after heart transplantation: association with big endothelin-1

BACKGROUND: Endothelin, a peptide with strong vasoconstrictive and mitogenic properties, has been found to increase after cardiac transplantation. We therefore assessed the association between its precursor peptide, big endothelin-1, and intimal hyperplasia and coronary flow reserve after heart transplantation. METHODS: Thirty-five patients without hemodynamically significant coronary artery disease after heart transplantation were investigated: Average peak flow velocity in the left anterior descending artery (LAD) was assessed by intracoronary Doppler at baseline as well as after injection of adenosine; coronary flow reserve was calculated as a ratio of both and was corrected for patient age and baseline average peak flow velocity. Lumen, intima + media and total vessel area were measured by intracoronary ultrasound. The plasma concentration of big endothelin-1 in venous blood was determined by radioimmunoassay. RESULTS: Patients with elevated big endothelin-1 levels (>2 fmol/ml) tended to have a decreased corrected coronary flow reserve (2.60 +/- 0.9 vs 3.21 +/- 1.0, p = 0.078). They also had a significantly larger intima + media area (5.82 +/- 2.9 vs 2.37 +/- 2.9 mm(2), p = 0.004) and total vessel area (18.36 +/- 5.8 vs 12.81 +/- 4.8 mm(2), p = 0.012) than those with normal plasma concentrations. CONCLUSIONS: Our study suggests an association between elevated big endothelin-1 plasma levels and the development of intimal hyperplasia and reduction of coronary flow reserve after cardiac transplantation.     

Alcohol controls and Aboriginal society: The effects of the Northern Territory restricted areas legislation

The “restricted areas” provisions of the Northern Territory Liquor Act constitute a preventative policy aimed at reducing the effects of alcohol abuse, particularly on Aboriginal communities. Under the provisions, communities can apply to be declared “dry” or semi-restricted with respect to liquor. Since their inception in 1979, the provisions have given rise to continuing controversy. This paper addresses some of the issues associated with the controversy. Patterns of alcohol consumption on “dry”, semi-restricted and unrestricted communities are compared, and the incidence of apprehension for public drunkenness before and after restricted area declarations is examined. The paper also discusses the provisions under which vehicles implicated in acts of illicit “grog-running” are forfeited to the NT Government. It is concluded that the restricted area provisions are associated with reduced levels of alcohol consumption and apprehensions for drunkenness, and are therefore beneficial in outcome. However, it is also argued that at present the provisions are flawed in that, while some aspects serve to promote community control over alcohol consumption, other elements have the effect of undermining community control and responsibility.     

Pediatric intracranial pressure monitoring in hypoxic and nonhypoxic brain injury

We reviewed the results of all pediatric patients undergoing intracranial pressure (ICP) monitoring in a 2-year period at our institution. The outcome of patients suffering hypoxia or ischemic injuries (HII) is compared to those suffering non-hypoxic or non-ischemic injuries (NHII). Thirty-four patients had ICP monitors placed during the study period. Inconplete patient information led to the exclusion of 5 patients. An additional 5 patients were excluded because no measures to control ICP were taken after the monitor was placed. Twenty-four patients required treatment for raised ICP (hyperventilation, 24; mannitol, 19; barbiturate coma, 6). Admission Glasgow Coma Score in patients suffering HII (median score 5) and NHII (median score 6) were not significantly different (Mann-Whitney U Test). Only 2 of 8 patients with HII were near-drowning vietims. The remaining 6 had HII from other causes (5 survivors of various forms of asphyxia and 1 of cardiac arrest). All 8 patients had poor outcomes (1 severely disabled; 7 died). The 16 patients with NHII had a variety of diagnoses (6 trauma, 5 encephalitis, 4 bacterial meningitis, 1 diabetic ketoacidosis). Among these, 6 had good outcomes and 10 poor outcomes (2 severely disabled, 2 vegetative, and 6 died). The difference in outcome between patients with NHII and HII is significant at P=0.059 (Fischer Exact test). Patients with NHII may benefit from ICP monitoring. Patients with HII from near-drowning and other causes did not appear to benefit from ICP monitoring and interventions directed at controlling ICP.